A fertiliser is a natural or artificial substance containing chemical elements (such as nitrogen, phosphorus and potassium) that improve crop growth and productivity.

Mineral fertilisers are fertilisers manufactured using chemical and/or industrial processes or extracted from organic materials containing carbon. They are also called chemical fertilisers, artificial fertilisers or inorganic fertilisers.

They include:
- Simple mineral fertilisers, such as urea, ammonium nitrate and sulphate.
- Complex mineral fertilisers, such as nitrogen, phosphorus and potassium mixtures.
- Organic-mineral fertilisers, such as calcium cyanamide.

Fertilisers derived from organic sources, such as animal products (e.g. livestock manure, dried blood, hoof and bone meal), plant residues or human sources (e.g. sewage sludge), contain carbon and nutrients of solely biological origin, and exclude material which is fossilized or embedded in geological formations.

An organo-mineral fertiliser is a co-formulation of one or more inorganic fertilisers and organic fertilisers.

Soil amendments are compositions capable of modifying the chemical or physical condition of soils for agricultural purposes. Products used to correct soil acidity are called liming materials and contain calcium or magnesium oxides, hydroxides, carbonates or silicates.

Soil conditioners (or soil improvers) are mixtures of fertilisers and other compounds, which are primarily used to maintain, improve or protect the physical structure, chemical properties or water retention capacity of soils for agricultural purposes. Examples of these compounds are water retention polymers, sand and clay materials.

Utilised agricultural area fertilised

In the 2020 census, research is carried out on utilised agricultural areas fertilised with mineral fertilisers and manure. A distinction is made between:
- Total UAA fertilised with mineral fertilisers
- Total UAA fertilised with manure

Manure exported from and imported to the agricultural holding

The net amount of manure transported off (exported) and brought onto the agricultural holding (imported) is studied.

A distinction is made between:
- Net export of liquid manure from the holding. Cubic metres of liquid manure imported to or exported from the agricultural holding for direct use as fertiliser or for industrial processing, regardless of whether it is sold, bought or exchanged free of charge. Also includes liquid manure used for energy production which will then be reused in agriculture.
- Net export of solid manure from the holding. Tonnes of solid manure imported to or exported from the agricultural holding for direct use as fertiliser or for industrial processing, regardless of whether it is sold, bought or exchanged free of charge. Also includes solid manure that has been used for energy production and will later be reused in agriculture.

Organic and waste-based fertilisers other than manure used on the agricultural holding

The number of tonnes of organic and waste-based fertilisers other than manure used on crops on the agricultural holding is studied.

Green manure is excluded.

Manure application techniques

Manure application techniques are important for reducing ammonia emissions, greenhouse gas emissions and for leaching nitrogen.

Both the soil incorporation time and the method used have implications for the amount of emissions.

Immediate incorporation of manure involves techniques which enable immediate incorporation of solid or liquid manure. For effective abatement, incorporation should occur as quickly as possible. This means that the manure applied is directly incorporated by a manure or slurry spreading machine, or the spreading machine is immediately followed by another machine that incorporates the manure into the soil (chisel or disc ploughing).

The 4-hour threshold set by experts can be considered the approximate time limit for identifying immediate incorporation.

Solid manure is defined as domestic animal droppings, with or without litter, which may contain a small amount of urine.

Liquid manure is urine from domestic animals which may contain a small amount of excrement and/or water.

Semi-liquid manure, or slurry, is a mixture of domestic animal droppings and urine which may contain water and/or a small amount of litter.

Broadcasting

Broadcasting can be used to apply solid, semi-liquid and liquid manure.

Application techniques include box spreaders, tank wagons, hoses and irrigation systems. Broadcasting requires the least amount of time and energy and results in a uniform application pattern. However, surface broadcasting promotes the release of nitrogen into the atmosphere and the organic fraction decomposes slowly on the soil surface..

Band spreading

Band spreading is the placement of fertiliser in a concentrated layer or location (band) in the soil, typically 8-15 cm below the surface. Fertiliser can be placed in the bands with the seed, below the seed, or both.

Spreading can be carried out using a:
- Trailing hose: Liquid or semi-liquid manure is discharged at ground level onto grass or arable land through a series of flexible hoses. Application between the rows of a growing crop is feasible.
- Trailing shoe: Normally, liquid or semi-liquid manure is discharged through rigid pipes which terminate in metal "shoes" designed to travel along the soil surface, parting the crop so that slurry is applied directly to the soil surface and below the crop canopy. Some types of trailing shoes are designed to cut a shallow slit in the soil to aid infiltration.

Injection

Injection methods are beneficial as they place liquid manure below the soil surface, eliminating both surface run-off on sloping soils and the volatilization of ammonia from manure on any soil. It also reduces odour. However, injection can significantly increase nitrogen loss through denitrification and leaching to groundwater. Injection equipment can be added to liquid and semi-liquid manure spreaders.

The following types of injection can be identified:
- Shallow slot (or open slot) injection: liquid manure is applied by placing it in shallow, vertical slots, typically about 50 mm deep and 25-30 cm apart, cut into the soil by a tine or disc. They are most commonly used on grassland.
- Deep slot (or closed slot) injection: liquid or semi-liquid manure (slurry) is applied by placing it in deep, vertical slots, typically about 150 mm deep, cut into the soil using specially designed tines. The tines are equipped with lateral wings which aid dispersion into the soil. Generally, these are used on arable land as they are more likely to physically damage grasses.

Broadcast manure application

Manure is spread over the surface of a plot of land or crops without using band spreading or injection techniques.

Incorporation within 4 hours
Applied manure that has been mechanically incorporated into the soil within 4 hours after broadcasting.

Incorporation after 4 hours
Applied manure that has been mechanically incorporated into the soil between 4 and 24 hours after application.

No incorporation
Applied manure that has not been incorporated into the soil or has been incorporated more than 24 hours after broadcasting.

Manure application through band spreading

Liquid manure is applied to an area in parallel bands with no manure between them by means of a device (band spreader) attached to the end of a tanker or tractor for discharging liquid manure onto the soil.

Spreading can be performed using two techniques:
Trailing hose
Trailing shoe

Manure application by injection

Liquid manure is applied by placing it in slots made in the soil at varying depths depending on the type of injector.

There are two types of injection according to the depth of the slots:
Shallow slot (open slot): manure is placed in shallow slots, usually around 50 mm deep, irrespective of whether the slots are left open or closed after application.
Deep slot (closed slot): manure is placed in deep slots, usually around 150 mm deep, which are closed after application.

Manure storage facilities and capacity

Storage facilities are a potential source of pollutant emissions.

In addition to reducing ammonia emissions, manure storage is very important for reducing nitrous oxide and methane emissions, as well as for nitrate and phosphorus leaching and leakage.

In some cases, storage facilities are also part of treatment systems (e.g. lagoons with anaerobic digesters).

A reduction in emissions can be achieved by using suitable cover.

Types of storage

- Manure storage in unconfined heaps, piles or stacks or in an open confinement area, normally for several months.
- Manure stored in confined compost piles, which are aerated and/or mixed.
- Manure stored in pits below animal housing, with little or no added water, typically below a slatted floor in an enclosed animal housing facility, usually for periods of less than a year.
- Manure stored in deep litter systems, which is accumulated over a production cycle, which can last from 6 to 12 months.
- Liquid manure storage without cover or in ponds, usually for a period of less than a year.
- Liquid manure storage with permeable cover, in tanks or ponds, usually for a period of less than a year, covered with a permeable cover (such as clay, straw or natural crust).
- Liquid manure storage with impermeable cover, in tanks or ponds, usually for a period of less than a year, covered with an impermeable cover (such as high-density polythene or negative pressure covers).
- Manure (liquid or solid) stored in other facilities not classified elsewhere.
- Daily spreading of manure, which is routinely removed from an animal housing facility and applied to cultivated land or grassland within 24 hours of excretion.

Capacity of manure storage facilities

Refers to the number of months that manure produced on the agricultural holding can be stored without risk of leakage and without accidental emptying.

- Manure stored in confined compost piles.
- Liquid manure storage in pits below animal housing.
- Manure storage in deep litter systems.
- Liquid manure storage, irrespective of cover.
- Manure (solid or liquid) stored in other facilities not classified elsewhere.